Introduction

Irrigation is the artificial application of water to the soil to aid in the growth of crops. In India, where agriculture plays a major role in the economy and provides employment to nearly half of the population, irrigation is essential due to the uneven and seasonal nature of rainfall. It supports the cultivation of multiple crops, improves productivity, ensures food security, and stabilizes farmers’ incomes. Understanding the types of irrigation systems, their historical development, and regional practices is crucial for sustainable agricultural growth and better water resource management.

What is Irrigation?

• Irrigation is the artificial supply of water to the soil for crop production.
• It helps in providing moisture essential for the growth and development of plants.
• Ensures crop production even in areas where rainfall is insufficient or irregular.

Timeline of Irrigation Development

World

• 6th millennium BC: Early signs of irrigation found in Mesopotamia and Egypt.
• 4th millennium BC: Canal irrigation practiced in the Zana valley in the Andes Mountains, Peru.
• 2600 BC: The Indus Valley Civilization in present-day Pakistan and North India used early canal systems.
• 1800 BC: Egyptian Pharaoh Amenemhet III used Lake Fayum for irrigation.
• 800 BC:
  • Qanats in ancient Persia, using vertical wells.
  • Noria water wheels in North Africa, designed by Roman settlers.
• 300 BC: King Pandukabhaya of ancient Sri Lanka built artificial reservoirs.
• 250 BC: The Dujiangyan System in China’s Sichuan region, still operational today.

India

Ancient India

• Vedas refer to canals and wells.
• The Indus Valley Civilization flourished on riverbanks, using early canal systems and small well irrigation.
• The Girnar reservoir (3000 BC) is an example of early storage infrastructure.
• Chola dynasty:
  • Built the Grand Anicut on the Kaveri River.
  • Constructed several tanks to store water.

Medieval India

• Ghiyasuddin Tughlaq initiated canal constructions.
• Firoz Shah Tughlaq was known as the greatest canal builder.
• Agricultural prosperity led rulers like those of the Delhi Sultanate, Vijayanagar Empire, and Mughal Empire to invest heavily in irrigation.
• Baburnama, the memoirs of Babur, describe irrigation methods of the time.

British India

• 1901: First Irrigation Commission formed after major famines.
• Between 1910-1950, government-run irrigation grew:
  • Canal irrigation increased by 2% annually.
  • Well irrigation grew by 0.54% annually.
• Major projects included:
  • Upper Ganga Canal
  • Periyar Dam
  • Betwa Canal
  • Canals in Krishna-Godavari systems

Why India Needs Irrigation

• 80% of rainfall occurs between June and October, creating seasonal dependency.
• Uncertain monsoon patterns can lead to crop failures.
• Rainfall is unequal:
  • Western Ghats: >200 cm
  • Parts of Rajasthan: <50 cm
• Agriculture employs 50% of India’s population.
• Ensures food security by supporting crop production throughout the year.
• Facilitates the growth of secondary crops during dry months.
• Essential for crops like rice (needs water) and HYV seeds (require continuous watering).
• Helps in changing cropping patterns and enhancing cropping intensity.
• South Indian rivers are non-perennial, making artificial irrigation necessary.
• In hill regions, rainwater flows down quickly:
  • Irrigation is needed for tea, coffee, rubber plantations.
• Sandy or loamy soils absorb water quickly:
  • Irrigation maintains moisture levels.
• Constant water supply provides stability to farmers.
• Promotes adoption of modern farming techniques.
• Irrigation helps combat droughts and famines.
• Enables the cultivation of diverse crops:
  • Rabi (e.g. wheat, potatoes)
  • Kharif (e.g. rice)
  • Cash crops (e.g. sugarcane, cotton, tobacco)
• India lacks rainfall during winter (Rabi season).
• High temperature and evaporation due to tropical climate.
• Prevents water scarcity during dry seasons.

Types of Irrigation in India

Irrigation in India can be classified into several types based on the source of water, mode of delivery, and technological approach. Each type has its own requirements, advantages, and challenges based on geography, soil, climate, and resources.

Well and Tube Well Irrigation

• Well irrigation involves digging a hole in the ground to access subsoil water.
• Tube well irrigation uses a deeper well, fitted with a tube and pump set to lift water.

Requirements:

• Availability of groundwater.
• Presence of soft rock for easy digging.

Major areas:

• Northern Plains
• Deltaic regions: Mahanadi, Godavari, Krishna, Cauvery
• Deccan Trap regions with weathered layers

Advantages:

• Simple and inexpensive
• Provides immediate water access
• Water may contain useful chemicals like nitrate, chloride, sulphate
• Can be dug anywhere

Disadvantages:

• Limited area coverage
• Overuse can dry up the well
• Tube wells need electricity or diesel
• Can deplete groundwater making it unfit for use

Canal Irrigation

• Canals draw water directly from rivers or reservoirs and distribute it through a network.

Requirements:

• Flat land for canal construction
• Soft rock layers for easy excavation
• Perennial water source
• If from flood streams, needs seasonal river floods

Major areas:

• Northern Plains: Punjab, Haryana, Uttar Pradesh
• Southern India: Coastal and deltaic regions

Advantages:

• Constant water supply in perennial regions
• River sediments enhance soil fertility
• Useful in multipurpose projects
• Though initial cost is high, it is economical long-term

Disadvantages:

• Only suitable for plain and valley regions
• High capital cost
• Risk of waterlogging from unlined canals
• Leads to marshlands, encouraging mosquito-borne diseases
• Floods during rainy seasons
• Limited geographical reach

Tank Irrigation

• Involves storing water in natural or man-made depressions surrounded by bunds.

Requirements:

• Smooth surface land to form depressions
• Hard rock base to prevent water percolation
• Proximity to river beds for easy filling

Major areas:

• Peninsular India: Tamil Nadu, Andhra Pradesh, East Karnataka, East Madhya Pradesh, East Maharashtra

Advantages:

• Mostly natural, thus low construction cost
• Individual farmers can own tanks
• Long lifespan if built on rocky beds
• Can also be used for aquaculture, providing extra income

Disadvantages:

• Not useful in dry seasons
• Silting of tank beds needs regular desilting
• High evaporation loss
• Hard rock areas make it tough to transfer water to fields

Modern Irrigation Techniques

Modern irrigation techniques aim to maximize water use efficiency, reduce wastage, and enhance crop productivity. These methods are particularly important in water-scarce regions and help in adapting to changing climate patterns.

Subsurface Irrigation

• Involves raising the water table artificially to supply moisture to plant roots through capillary movement.
• Also called seepage irrigation.

How it works:

• Water is raised using pumping stations, canals, weirs, and gates.

Advantages:

• Very low evaporation losses
• Water level can be controlled for different crops
• No waterlogging
• Does not occupy agricultural land
• Low maintenance cost

Disadvantages:

• High installation cost
• Risk of soil becoming saline or alkaline
• May damage neighboring lands
• Labour-intensive
• Frequent pipe maintenance required
• Not suitable for all crop types

Surface Irrigation

• Water flows over the field and is distributed by gravity.
• Also known as flood irrigation.

Flooding Method

What it is:

• Water is allowed to flow freely in all directions over the land.

Best for:

• Uneven lands and areas with cheap, abundant water

Advantages:

• Suitable for shallow soils
• Can be used where land leveling is expensive
• Low installation and operation costs
• System is not easily damaged by livestock

Disadvantages:

• Large water loss through runoff and percolation
• Can cause soil erosion
• Loss of fertilizers and FYM
• Very inefficient – only 20% water used by plants
• Uneven water distribution and crop growth

Bed/Border (Check Basin) Method

What it is:

• Fields are divided into small beds with bunds; water is channeled between rows.

Advantages:

• More efficient and uniform water application
• Low maintenance and labor cost

Disadvantages:

• High initial cost
• Requires leveled land
• Evaporation loss
• Bunds reduce sowing space

Basin Method

What it is:

• Water is applied to small, enclosed areas (basins), useful for orchards, rice, jute.

Advantages:

• Variable water supply
• No runoff loss
• Quick irrigation
• Fertilizer and manure retention

Disadvantages:

• Needs leveled land
• Not suitable for dispersive soils
• High initial cost

Furrow Method

What it is:

• Water flows through furrows between plant rows.

Best for:

• Row crops like potatoes, cotton, sugarcane, vegetables
• Suitable for sloped land

Advantages:

• High efficiency
• Adaptable to many soils and crops
• Low maintenance
• Minimal water contact with plant stems

Disadvantages:

• Needs skilled labor
• Hazard for machinery
• Requires proper drainage

Localised or Micro Irrigation Methods

Micro irrigation, also called precision irrigation, uses low pressure and delivers water directly to the plant roots. These systems save water, enhance crop yield, and minimize weed growth and soil erosion. Micro irrigation is highly suitable for water-scarce and uneven terrain regions.

Sprinkler Irrigation

What it is:

• Water is sprayed over the crops through high-pressure sprinklers or guns.
• Also called Overhead irrigation or Solid set irrigation.

Types:

• Rotating head sprinklers
• Perforated pipe systems

Advantages:

• Saves 30%–50% water
• Eliminates need for water channels, reducing water loss
• No risk of runoff or soil erosion
• Effective in shallow soils
• Useful for a wide range of topographies
• Can be mobile or permanent
• No bunds needed, so more usable land
• Can also be used for frost protection and micro-climate control
• Low labour cost
• Can apply fertilizers, pesticides through the spray

Disadvantages:

• High initial cost – unaffordable for small farmers
• High operating and maintenance costs
• Components like nozzles and pipes require regular maintenance
• Evaporation losses during hot weather
• Wind disturbs water distribution
• Can cause fruit rot in sensitive crops like tomato and strawberry

Drip Irrigation

What it is:

• Water is delivered drop by drop directly at the root zone.
• Also called Trickle irrigation.
• Traditional versions used by tribes in Northeast India with bamboo pipes.

Advantages:

• Water use efficiency is over 90%
• Increases crop yield by up to 230%
• Minimum evaporation and no runoff
• Fertilizer use efficiency increased by 30%
• Saves energy, fertilizer, and labour costs
• Suitable for:
  • Saline, waterlogged, sandy, and hilly lands
  • Undulating terrain
  • Expensive water/labour regions
• Allows recycled water use
• Requires no land leveling
• Avoids weed growth, soil erosion
• High uniformity in water distribution
• Easy fertigation (fertilizer delivery through irrigation)

Disadvantages:

• Needs technical knowledge for installation
• Requires careful assessment of:
  • Topography
  • Soil
  • Crop
  • Climate
• Costly (~₹40,000 per hectare)
• Pipes may suffer rodent or sun damage
• Improper filtering causes clogging
• Requires leaching to prevent salt buildup at root zones
• Credit access issues for small farmers
• Fragmented landholdings make adoption difficult
• Not effective for herbicides or fertilizer that need surface activation

Other Irrigation Methods and Traditional Water Harvesting in India

Apart from well-known irrigation systems, several innovative and traditional techniques have been developed to suit specific geographical and cultural needs. These methods are highly effective for sustainable water management, especially in rural and remote areas.

Other Irrigation Methods

Fertigation

What it is:

• Application of fertilizers and other water-soluble substances through irrigation systems.

Where used:

• Widely practiced in commercial agriculture and horticulture for high-value crops like vegetables, fruit trees, and ornamentals.

Why used:

• To add specific nutrients or correct nutritional deficiencies based on plant analysis.

Advantages:

• Enhances nutrient absorption by plants
• Reduces fertilizer wastage and leaching
• Allows micro-dosing, giving plants just enough nutrients
• Ensures uniform fertilizer distribution
• Decreases risk of soil-borne diseases

Disadvantages:

• Not all fertilizers dissolve easily
• Requires accurate concentration of solutions
• Excessive use of chemicals can harm the soil
• Needs a separate water supply to avoid contamination of drinking water

Earthen Pot Irrigation

What it is:

• A porous clay pot is buried up to its neck and filled with water.
• Surrounding plants absorb moisture through osmotic pressure.

Advantages:

• Very low-cost, eco-friendly, and efficient
• Suitable for kitchen gardens or small plots

Jaltripti (Double-Walled Pot)

What it is:

• Inner pot holds the crop, and outer pot stores water.
• Ensures consistent moisture for the crop from the outer to the inner pot.

Tubeponics

What it is:

• A method developed in Israel where water is injected into plant stems or soil through tubes.
• Aimed at precise delivery of moisture and nutrients.

Traditional Water Harvesting Techniques of India

India has a long history of community-based water harvesting that is adapted to local climates, topography, and cultural needs.

Jhalaras

Where: Found in Jodhpur, Rajasthan
What: Rectangular stepwells with tiered steps
Example: Mahamandir Jhalara, built in 1600 AD

Talabs and Bandhis

Where: Common in Bundelkhand and Udaipur regions
What:

• Talab: Small water reservoir (<5 bighas)
• Bandhi: Medium-sized lake
• Sagar: Large lake
• Used for irrigation, drinking, and domestic use

Ahar-Pyne System

Where: South Bihar
What:

• Ahars: Reservoirs built at the end of diversion channels (Pynes)
• Designed to harvest floodwater

Khadin and Johad

Where: Karnataka, Odisha, Rajasthan
What:

• Small earthen check dams
• Used to store rainwater and recharge groundwater

Panam Keni

Where: Used by Kuruma Tribe, Wayanad, Kerala
What:

• Stepwells made from hollowed toddy palm stems
• Long-lasting and sustainable technique

Zabo System

Where: Nagaland
What:

• Rainwater is collected at hilltops
• Flows through cattle yards (collects dung/urine)
• Ends up irrigating paddy fields through ponds

Zings

Where: Ladakh
What:

• Small tanks that collect melting glacier water

Kunds

Where: Western Rajasthan, Gujarat
What:

• Saucer-shaped catchments with a central underground well
• Effective in arid regions

Dams and Irrigation Projects in India

Dams are a crucial part of India’s irrigation infrastructure. They store water safely and allow for controlled supply throughout the year. Dams are built for multiple purposes including irrigation, hydroelectricity, flood control, and drinking water supply. India has also launched several government schemes to promote irrigation development and water conservation.

Purpose of Dams

• Safe storage of water during the monsoon
• Helps in controlled irrigation throughout the year
• Used for multi-purpose projects like drinking water, power generation, and fisheries

Factors to Consider Before Dam Construction

• Rock or soil base should be strong enough to bear the weight of the dam and water
• Reservoir basin must be watertight to minimize seepage and water loss

Classification of Dams

Embankment Dams

What it is:

• Made of earth fill or rock fill
• Uses locally available materials

Types:

• Earth fill embankments
• Rock-fill embankments with a core of earth, concrete, or bitumen and an outer layer of crushed rock

Advantages:

• Suitable for all river valley types – steep or wide
• Can be built on different foundations – from hard rocks to permeable soils
• Low cost due to use of natural materials

Disadvantages:

• Prone to damage from floods or earthquakes
• Leakage and seepage risks are higher compared to concrete dams

Concrete Dams

What it is:

• Built using mass concrete

Types:

• Gravity dams: Stable due to their weight
• Buttress dams: Supported by angled walls on the downstream side
• Arch dams: Curve-shaped, transfer pressure to valley walls

Advantages:

• Durable and less likely to leak
• Suitable for complex engineering designs
• Easier to construct and maintain

Disadvantages:

• Very expensive
• Not suitable for all valley types due to site-specific needs

Irrigation Potential and Classification of Projects

• India has an irrigation potential of 139 million hectares, making it the largest irrigated area in the world.

Classification by Planning Commission:

• Major Irrigation Schemes: Cultivable Command Area (CCA) > 10,000 hectares
• Medium Irrigation Schemes: CCA = 2,000 to 10,000 hectares
• Minor Irrigation Schemes: CCA < 2,000 hectares

Key Government Projects and Schemes

Rural Infrastructure Development Fund (RIDF), 1995-96

• Created to fund rural infrastructure, including irrigation, especially in the wake of recurrent droughts

Accelerated Irrigation Benefits Programme (AIBP), 1996-97

• Provides loan assistance to states
• Aim: Finish incomplete irrigation projects

National Mission on Micro Irrigation (NMMI), 2006

• Promotes drip and sprinkler irrigation to increase water efficiency
• Merged into National Mission on Sustainable Agriculture (NMSA) in 2014

Pradhan Mantri Krishi Sinchayee Yojana (PMKSY), 2015

• Aims at ‘Har Khet Ko Pani’ (water to every field)
• Encourages precision irrigation – ‘More crop per drop’
• Focuses on aquifer recharge, sustainable water use, and public-private investment

Funding Pattern:

• 75:25 Centre-State ratio
• 90:10 in North-Eastern and hilly states

Components:

• Water Resource Management: Groundwater development, rainwater harvesting, lift irrigation, MGNREGA integration
• Per Drop More Crop: Drip and sprinkler irrigation
• Watershed Development: Ridge area treatment, water harvesting, soil conservation

Water Management under NMSA

• Provides subsidies for:
  • Tube wells
  • Community tanks
  • On-farm ponds
  • Pipe systems
  • Secondary storage with protective lining

Issues in Irrigation and Suggestions to Improve Efficiency

Despite advancements in irrigation infrastructure, India faces several challenges related to inefficient water use, environmental degradation, and unequal access. Addressing these issues is crucial for ensuring sustainable agricultural development and water security.

Issues with Irrigation Practices

• Overuse and unscientific irrigation: Leads to serious water problems, such as the crisis in Punjab where excessive tube well use has lowered the water table.
• Waterlogging: Results from poor drainage and excess irrigation; makes soil unfit for cultivation.
• Water mining: Unregulated extraction of groundwater depletes aquifers.
• Soil/land subsidence: Occurs when groundwater is removed faster than it is replenished.
• Saltwater intrusion: Coastal irrigation leads to the intrusion of saline water, damaging crops and soil.
• Siltation in reservoirs: Reduces water storage and effectiveness of dams over time.
• Imbalanced regional development:
  • Over-developed: Western Maharashtra
  • Underdeveloped: Vidarbha, even within the same state
• Salty agricultural soils: In hot areas, evaporation draws salts to the surface, making land barren.
• Ecological disturbances:
  • Rivers dry up before reaching the sea.
  • Increases salination in river mouths and reduces fertile delta lands.
• Evaporation loss: Stored water in reservoirs evaporates significantly under high temperatures.
• Desertification: Groundwater depletion leads to land becoming arid and barren.
• Diseases:
  • Stagnant water encourages breeding of mosquitoes and Bilharzia snails.
  • Malaria outbreaks observed since British era, especially in canal areas like Upper Bari Doab Canal (1908, over 12,000 deaths).
• Reduced fishing and shipping opportunities:
  • As rivers dry, fish populations drop (e.g., Indus River, Pakistan).
  • Ships can’t navigate due to shallow waters.
• Soil leaching:
  • Marshy fields result in poor aeration for roots and microbes, impacting plant growth.

Issues with Irrigation Projects

• Over-reliance on water wells: Reduces groundwater levels.
• Bureaucratic inefficiency:
  • Projects delayed due to red tape
  • Leads to cost and time overruns
• Ageing infrastructure: Over 60% of Indian dams are more than 20 years old.
• Siltation in large dams: Reduces storage capacity and efficiency.
• Focus on expansion rather than efficient usage.
• Many major river basins have reached their maximum potential.
• Financial constraints: Large number of irrigation projects are pending.
• River water disputes: Common among Indian states and with neighboring countries.
• Environmental impact: Dam projects may submerge forests and wildlife habitats.
• Displacement: Large irrigation projects have displaced tribal communities and local farmers.

Suggestions to Improve Water Use Efficiency

• Promote drip irrigation for horticultural crops.
• Promote sprinkler irrigation for millets, oilseeds, and pulses.
• Encourage conjunctive use of both groundwater and surface water.
• Improve canal system efficiency and ensure proper drainage.
• Provide farmers with real-time information on water availability.
• Encourage recycling of surface irrigation water.
• Promote crop patterns suitable to local soil, water, and climate.
• Water auditing of irrigation projects should be made mandatory and used in decision-making.
• Reduce evaporation losses by using mulches to cover soil and retain moisture.

Conclusion

Irrigation is the lifeline of Indian agriculture, especially in the face of a variable monsoon, regional disparities, and a growing demand for food. While traditional systems laid the foundation, modern methods and policies have brought vast improvements. However, India’s irrigation sector faces serious challenges including water overuse, inefficient systems, ecological damage, and institutional bottlenecks. A sustainable future lies in combining technological innovation, traditional wisdom, and policy reforms to ensure that every drop of water is used wisely. With proper planning and farmer participation, irrigation can continue to play a transformative role in India’s agricultural and rural landscape.

1. Discuss the ecological and agricultural implications of over-reliance on groundwater-based irrigation in India.
2. Examine the role of traditional water harvesting systems in improving irrigation efficiency and water sustainability in semi-arid regions of India.
3. Evaluate the effectiveness of government schemes like PMKSY in addressing the irrigation challenges faced by small and marginal farmers.